This invention refers to the climatization of short, medium and long distance transport vehicle cabins for passengers and cargo, such as trucks, minibuses, as well as road-building and agricultural machinery and other means of locomotion. More particularly, it refers to an evaporating unit of the type which is mounted on the roof of the cabin and is provided with an external air intake, which is cooled and circulated inside the cabin. The cooling is generally carried out by passing the air through a radiator/evaporator made from a porous material which is kept humid, which fulfills the double function of thermal exchanger, taking heat from the air, and humidifier, which gives the sensation of the air having been cooled. The cabin is cooled by the lower temperature of the climatized air and by the evaporation of the humidity which comes in with the air. This invention refers specifically to the hot air intake for the evaporator.
These units are attractive due to their cost and lower maintenance compared with the traditional air conditioning units, furthermore they do not require to take any energy from the engine of the truck, which signifies likewise an operative saving as well as not reducing the available power of the transport vehicle for its own locomotion.
These air acclimatizers may also be adapted to other uses, such as transitory or precarious living quarters, for example, workshops. The advantage in these static installations is the avoidance in the use of compressors and the electrical consumption.
Acclimatizers of the type described in the previous section are known on the market. These units have a water deposit an a pump which circulates the water towards the evaporator in order to keep it humid. An electric ventilator sucks hot air through the intake, sucking it through the evaporator, where it is conditioned, giving up heat and absorbing humidity, prior to ventilating the climatized air towards the interior of the cabin.
These units are commercial successful due to their simplicity and the advantages already mentioned. Argentina Patent No. 235,114 and U.S. Pat. No. 3,867,486 describe acclimatizers with those characteristics. In both of the aforementioned patents, the evaporating unit comprises a plastic cabinet adapted for mounting on the roof of a cabin. The external air intake is made up of a grid positioned on the front of the cabinet, through which the hot air is sucked through an evaporator, the cooled air leaving through a gorge depending down from the base of the cabinet and into the cabin, through an orifice which has been made in the roof.
The cooled air which enters the cabin is relatively noisy and it has been discovered that important part of the noise transmitted by the air to the interior of the cabin comes from its passage through the intake grid in the front part of the aforementioned evaporating unit. The problem with this level of noise is aggravated by the higher speed of the modern trucks compared to previous models.
It has also been observed that the frontal flow of incoming air, because it is direct, is prone to encourage the entry of bugs and particles into the air intake, which is equipped with a filter. The accumulation of bugs and dirt trapped by the filter obstructs it progressively, reducing the cooling effect of the acclimatizer. The bugs and particles that get by the filter, due to their size, enter the cabin, which is disagreeable to the driver and occupants.
It has been found that this level of noise can be substantially reduced by intaking the air to be conditioned through the base of the unit. This solution has the added advantage of reducing the entry of bugs and particles to the intake.
In pursuit of these objectives and advantages, this invention comprises an evaporating unit for an acclimatizer whose front is substantially closed, thus avoiding the generation of noise due to the frontal intake of air against the conventional grid/filter system, wherein the air intake is placed in the base of the cabinet. Suitably, the air intake is made up of a grid arrangement distributed around the base of the cabinet, preferably surrounding the gorge which connects it to the cabin.
In addition to achieving a significant reduction of air noise in the cabin, which has been the main concern which has been addressed in the development of the invention, the preferred arrangement makes the air intake in the base surround the evaporator, increasing the flow surface through the porous tubular wall, resulting in a better use of and efficiency in the functions of cooling and humidifying the air.